Isotactic polypropylene and ethylene/propylene copolymers are often used in the industry to produce articles such as fibers, films, molded parts and nonwoven fabrics. Additionally, blending these polymers with other polymers has been the subject of past endeavors.
Slit film tapes prepared with polyethylene exhibit greater elongation and flexibility, higher elongation at break and lower tensile strength than stretched tapes prepared from other materials such as polypropylene. However, slit film tapes prepared from polyethylene suffer from inadequate processability. Polypropylene slit film tapes are produced by extruding a flat sheet that is slit into many narrow tapes. The tapes are then stretched in machine direction to reduce the thickness and to increase the tenacity (tensile strength divided by thickness). Typically, an anti-fibrillating masterbatch (AFMB) is added to remove the fibrillation of polypropylene, to reduce cost and increase stiffness of the slit film tapes.
It would be desirable to produce tapes, such as raffia tapes, having increased tensile strength and/or elongation, without losing or suffering significant loss in other properties. Moreover, would be desirable to reduce cost by either incorporating more AFMB or reducing the thickness while maintaining or improving the tenacity of the slit film tapes.